Square.



UNITED STATES.

PatentedNovember 24, 1903.

PATENT OFFICE.

TUVE ESBIORNSN, OF PHILADELPHIA, PENNSYLVANIA.

SQUARE.

SPECIFICATION forming part of Letters Patent No. 745,171, dated November24, 1903.

Application filed August I4, 1902. Serial No. 119,584. (No modeh) v i Toall whom t may concern.

Be it known that I, TUVE EsBioRNsoN, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inSquares, of

' which the following is a specification.

This invention relates to squares, and has for its object to provide asimple and efficient construction whereby the size of the square may bereadily reduced or enlarged as occasion may require. p

lVith this object in view the invention consists in the novelconstruction and combinations of parts, which will be hereinafter fullydescribed and claimed.

In the drawings, Figure l is an elevation of my improved square. Fig. 2is a similar view with the extension members removed. Fig. 3 is asectional detail as on the line 3 of Fig. l. y

1 designates my improved square, compris,- ing the usual long and shortarms 2 and 4, respectively, and the extension-pieces 5 5, which form, ineffect, a continuation of the arms.

The arms 2 4 and the extension-pieces 5 5 may be constructed of sheetmetal or any suitable material.

The arms 2 and 4 are preferably formed of one piece, as shown in thedrawings.

The outer ends of the arms 2 4 are provided with dovetail offsets 6 6,the respective sides of which constitute undercut projections, and theextension-pieces 5 5 are `provided with undercut or dovetail projections7 7, which are adapted to register with the offsets, and therebysecurely lock the extension-pieces 5 5 to the arms 2 4.

In order to maintain the extension-pieces 5 5 in line with the arms 2 4and to maintain the engagement of the dovetail projections 7 7 withtheir offsets 6 6, I provide slide-blocks 8 8. These slide-blocks aretted to V-shaped ribs 9 on the inner Walls of oppositely-disposedelongated openings l0 10 in the meeting ends of the arms 2 4 andextension-pieces 5 5.

The opening 10 in each extension-piece 5 is sufficiently long to receiveits block 8, and thereby permit the withdrawal of the latter from theopening 10 in the opposing arm.

By the above-described construction it will be seen that when the blocks8 occupy the positions shown in the drawings the extensionpieces 5 5 arerigidly locked to the arms 2 4 in line therewith and that if the blocks8 S be moved into the openings 10 10 in the eXtension-pieces 5 5 theblocks will be disengaged from the openings lO l0 in the arms 2 4,whereupon the extension-pieces may be readily removed from the square.

I claiml. A square comprising a pair of integral arms arranged at rightangles'to each other, an extension member, an undercut projection and anundercut offset at the meeting ends of said member and one of said arms;said pro-l jection being adapted to register with said offset to retainsaid extension member in engagement with one of said arms, said arms,extension member and projection being all of the same thickness and saidoffset extending from face to face of the square; and means fordetachably maintaining said projection within said offset. v

2. A square comprising a pair ofV integral arms arranged at right anglesto each other, an extension member, an undercut projection and anundercut offset at the meeting ends of said member and one of said arms;said projection being adapted to register with said offset to retainsaid extension member in engagement with one of said arms, said arms,extension member and projection being all of the same thickness and saidoffset extending from face to face of the square; oppositelydisposedopenings in the meeting ends of said member and Vone of said arms, and aslideblock fitted to said openings so as to be slid' ingly retainedwithin the latter, one of said openings being sufliciently long topermit the withdrawal of said block from the opposite opening.

In testimony whereof I afliX my signature in presence of two witnesses.

TUVE ESBIORNSON.

Vitnesses:

ROBERT K. PERKINS, ANDREW V. GROUPE.

